


the way that we fell

by warsfeil



Category: Ensemble Stars! (Video Game)
Genre: M/M
Language: English
Status: In-Progress
Published: 2018-03-31
Updated: 2018-10-31
Packaged: 2019-04-16 02:08:04
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 3
Words: 13,525
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14154357
Author URL: https://archiveofourown.org/users/warsfeil/pseuds/warsfeil
Summary: "The first time Kaoru sees a demon, his mother is still alive."In which Rei Sakuma is the king of hell, Kaoru accidentally makes a contract, there are angels involved, and Keito Hasumi really wants a break from being an onmyouji.





	1. Chapter 1

**Author's Note:**

> hello and welcome to the angel/demon au based on every zero-sum manga i've ever loved! tags will be updated as the fic progresses, as will this author's note.

The first time Kaoru sees a demon, his mother is still alive.

Kaoru had heard about demons before, of course. It was impossible to live in the world and _not_ know about demons. Even before he was old enough to go to school, his mother would tell him about them, read him stories from her old books from before the war and tell him how different things were long before she was ever alive. 

Seeing a demon is everything in the flesh is different from the stories. 

Kaoru’s mother sweeps him into her arms and stands her ground, the only person that Kaoru has ever heard of to try and square off against a demon. Kaoru doesn’t remember much of the encounter anymore, snapshots of memory that filter down through the years -- his mother’s perfume, the way the polish on her thumb was chipped, the way the moonlight filtered down the familiar storefronts, the red eyes of the demon as he stared at Kaoru’s mother like he could see into her soul.

“Then,” Kaoru remembers the demon saying, in a voice like a caress of darkness, “consider it a deal.”

Kaoru can never remember quite where the demon went, or how he vanished. He remembers that his mother bought him ice cream, afterwards, and didn’t talk about their encounter with the demon; everytime he would bring it up in conversation, she would refer to the demon as an _old friend_ until Kaoru overlaid false memories on the demon. A nice suit, his father’s aftershave. Human characteristics, until Kaoru can’t remember what the demon looked like or if he was really a demon at all. 

Kaoru’s memory of those red eyes never fades.

-

“...you listening?”

Kaoru’s eyes jerk away from the paper in front of him -- _list the top three mistakes people make in dealing with demons_ \-- and back to his classmate, offering an apologetic smile.

“Sorry, sorry,” Kaoru offers. Even the word “demon” can drag old memories up, and Kaoru wishes that what remains of the memory of that day wasn’t so vivid. Learning about the sixteen ways to kill a demon is a little more complicated when you keep remembering that time your mom took down a demon with nothing but words you can’t remember.

“Just be careful,” Kuro offers. He doesn’t seem to take offense at the fact that Kaoru is clearly not paying attention to… whatever he was saying; something about a recent cluster of demon attacks near the school, Kaoru thinks. “Let me know if you want to walk home with someone.”

“Ah, that kind of thing isn’t necessary,” Kaoru says, lifting his hand off his chin and straightening out. “My walk home isn’t very far.”

“Sure,” Kuro says, nodding. He doesn’t seem entirely convinced, but he accepts it nonetheless, which is why Kuro is probably one of Kaoru’s favorite classmates -- he’s the least likely to try and champion his way into a rescue that doesn’t need to be happening, but he’d also probably be reasonably useful in a fight.

Not that humans really have any chance against demons.

“It’s your birthday soon, isn’t it?” Kuro asks. His sheet is already filled out, all the answers to the information memorized since before they were ever assigned to the same class. Kaoru was at a disadvantage, when he started school, head full of his mother’s stories and nothing about the actual ways to deter demons.

“Few weeks away,” Kaoru says, offering a smile that’s a little more wane than he would like. His birthday is just another reminder of how close the future is, pressing down around him. The last thing he wants is to deal with politics and arranged marriages and his father, but every day brings him closer to the point where his sister won’t be able to shield him anymore. 

In some ways, it’ll be a relief; he’s tired of watching other people suffer instead of him.

“Doing anything special?”

“I might skip,” Kaoru says, shrugging a shoulder. He hasn’t given a whole lot of thought to the matter. He doesn’t have a girlfriend, at the moment, so there’s no plans there, and he’d rather celebrate their birthday rather than his own. It sounds nice, to be able to wrap his arms around a girl and watch a movie, to watch one laugh, to enjoy a piece of cake. 

He’ll probably just wind up at the beach again. If he wears the right jacket, he can probably stay out most of the day without getting sick, even if he can’t go in the water. Sea creatures aside, it’s entirely too cold this time of year.

“No one’ll stop you,” Kuro offers with a smile, congenial and easy. For someone who looks so rough around the edges, Kaoru’s found that he really is one of the people that’s easiest to get along with in school. Kaoru doesn’t form relationships with guys all that easily, so it’s kind of a relief to have someone he can sort of call a friend that doesn’t actually expect all that much from him. 

The class bell rings, and Kaoru puts his work sheet into his bag without thinking about it; he remembers the top three mistakes that people make when dealing with demons, but actually writing them feels like more effort than he wants to expend right now. There’s something about today that feels _off_ , that has him caught in the memories of the past instead of his own present, and he can’t quite shake it.

The cloudy sky is a monotone cast over the entire world, as Kaoru leaves the carefully warded school grounds. He has absolutely no intention of heading home -- not since both his siblings moved out -- and he has even less intention of trying to put a single bit of hard work in when he could, instead, go visit the cute waitress at the nearby coffee shop. It looks like it’s threatening to rain, and Kaoru definitely doesn’t have an umbrella, but that’s a sacrifice he’s prepared to make if her can make Sayuri-chan smile for a little while.

Kaoru pulls his phone out to text her and make sure she’s working, having acquired her number the previous week after a bit of medium-light flirting. A droplet of rain hits the screen, and he brushes it out of the way on autopilot, trying to select the best emoji to fit the flirtatious nature of the text. Another droplet hit, and Kaoru smears his thumb through it again. He didn’t think it was raining that hard.

The drop smears red across his screen, and Kaoru makes the first of the most common mistakes in dealing with a demon: he freezes. Then he looks up.

The demon he saw with his mother was almost human, but this demon is straight out of his elementary school textbooks -- too-long limbs and more teeth than Kaoru can count, sickly white skin stretched over bone and ligament with no regard for aesthetic. It’s perched on the roof of the shop, blood dripping from its mouth, and Kaoru can see fabric hanging from a jagged tooth.

An apron, to be specific. With a very familiar cafe logo imprinted on the front.

“Sayuri-chan?” 

The demon only licks its teeth with a tongue that’s entirely too long.. It doesn’t have eyes, but Kaoru gets the feeling that it’s looking at him anyway -- 

Kaoru makes the second mistake when he turns his back on it to run. His cellphone falls from fingers that refuse to respond to him, crashing to the ground with a sound that barely registers. He isn’t his mother, he can’t stand against something like that, he doesn’t remember what she said or what to do. His mother isn’t around to protect him, and in the face of a creature as terrifying as this, now that he’s old enough to understand the danger, there’s only panic in his mind.

“Hel--” Kaoru starts, and that’s as far as he gets before the demon is on him, slamming into his back like a cannonball and knocking him to the ground. The world spins dangerously, and Kaoru scrabbles against the damp pavement. A part of him reflects on the absurdity of being eaten by a demon in a back alley just because he didn’t bother to walk home in a group. It’s a stray thought that surfaces, unconnected to the rest of his mind, an outlier in a sea of panic.

“Get off, get off--” Kaoru barely recognizes his voice when it’s so high with terror, but he can feel claws pressing into his shoulder and breaking the skin open. The pain blossoms across his mind but doesn’t quite register. Nothing quite registers.

He hopes no one hears him and comes to investigate; the last thing he wants is someone else getting eaten by a demon that managed to break through the city’s defenses. 

“Stop,” Kaoru says, because he has to be doing something and trying to push himself up isn’t working with the demon’s weight on his back. He can feel the thing’s breath on him, acrid and humid and absolutely disgusting, and Kaoru’s fingers press against the ground, scraping his nails as he tries to wiggle away. He elbows it, and manages a solid hit, and the demon goes _flying_.

Kaoru doesn’t question it. He gets up and starts running again, too panicked to even think about the fact that he can’t possibly outrun a demon. If he can get inside somewhere, they can hold out long enough to get the onmyouji out. The nearest shrine isn’t that far, it wouldn’t take them long to arrive. 

Kaoru’s shoulder is aching, and he can feel blood running down his arm and dripping off his fingers. Everything feels like it’s tilting too far to the side, and he’s fairly certain he’s going to wind up with a hell of a concussion, but he doesn’t have time to worry about that. If he can make it back to the main road, then maybe he can live through this with just some scars. Girls like scars, he’ll be fine--

Except that there’s another demon blocking the exit. A horrible, skinless creature with too many eyes to make up for the fact that the first demon doesn’t have any, it seems. It stares at Kaoru with every one of its eyes, and Kaoru stops running, because there’s nowhere to go. There’s a demon on every side, it seems like, and Kaoru feels abruptly calm.

He knows with a desperate finality that he’s about to die, and with that realization comes a sense of peace that he wasn’t anticipating. 

“Shit,” Kaoru says, and his tone is entirely too light for the situation, even if he says it through clenched teeth. Without meaning to, Kaoru thinks about his mother; he remembers her staring down a demon, remembers feeling no fear when he was safe in her arms. Nothing could have harmed him, then. She could have taken on both of these demons and won. “Mom…”

Kaoru closes his eyes. He’ll see her soon, won’t he? He can hear the demons getting closer, one on each side -- one of them roars, and Kaoru is knocked back to the ground, backwards this time, cracking the back of his skull as heavily as he’d smacked the front. There’s another roar, and Kaoru braces himself for a blow that never comes.

Kaoru counts to five and opens his eyes to look at the demon. The demons, because now there’s three -- a third one there, shaped like a human. He might resemble one, but his inhumanity is obvious in the way that he fights, taking on both of the other demons without much apparent difficulty. There’s a blast of fire, and Kaoru can hear alarm bells ringing in the distance, every ward in the area flaring up to scream _demon, demon_ at everyone in the city.

The new demon cascades his hand through the chest of the long-legged demon while the demon that’s all eyes burns, writhing in a fire. The corpses drop almost in unison.

_Consider it a deal_ , Kaoru’s memory echoes, the uselessly repeating nostalgia springing back to the forefront of his mind. 

The demon looks at Kaoru with eyes as red as blood.

_Protect him,_ Kaoru’s mother had said, clenching her son in her arms when she’d run into the demon. _Protect him from your kind. I’ll do anything._

_Consider it a deal_.

Kaoru climbs back to his knees, brain scrambling to try and make sense of the situation. Should he run? Should he stay? Is he still as good as dead? There’s blood from the fight on the demon’s arm, and a scratch on his cheek that bleeds as red as any human, and Kaoru doesn’t know what to make of it.

“Hakaze Kaoru-kun,” the demon says, stepping towards him. He’s like every demon from Kaoru’s mother’s stories; beautiful demons that come to seduce, to lure their victims into a false sense of security before they’re devoured. Demons that shouldn’t exist anymore -- weren’t they all dead, after the war?

“Who the hell…?” Kaoru says. The demon stops when he’s in front of Kaoru, drops to one knee with a creak of leather pants that look like they’re actually painted onto him. The demon reaches out, gloved fingers sliding underneath Kaoru’s chin to force eye contact. 

Kaoru’s broken every single rule of dealing with demons, today, so he shouldn’t be too surprised when the demon’s gaze quite literally takes his breath away. It feels like finality; like accomplishing something Kaoru didn’t even know he was working towards; like he’s gotten back something he didn’t even know he was missing.

“My name is Rei Sakuma,” the demon says, and the jolt of hearing a demon’s true name spins in Kaoru’s stomach like alarm bells. “The king of hell. I made a promise to your mother.”

_Consider it a deal_ , Kaoru remembers, and the image he’d tried to disguise of the demon from his childhood comes back full force. All the false thoughts Kaoru tried to use to hide the memory fall away, and there’s only this man: a demon’s eyes and a human’s body.

“My mother is dead,” Kaoru says. He should be pulling away from Rei. He should be running. No, that’s not right -- you can’t outrun a demon -- but Kaoru knows protection spells, even if he isn’t good at them; the alarms are blaring and he just needs to buy some time; Kaoru could do any number of things that aren’t staying here on his knees in the rain with a demon’s hand on his chin.

“That doesn’t change the promise,” Rei says. He lifts his other hand to his mouth, tugs the glove off with his teeth. The sight of fangs in Rei’s mouth makes Kaoru’s stomach do another wary flip, but he can feel the mythical allure of Rei’s brand of demonic magic working already. His shoulder hurts more as the adrenaline fades, panic pulled away by unearthly beauty. 

The king of hell is dead, Kaoru thinks. He died before the war; he’s why the war happened, why hell was turned loose on earth and the world had to learn to cope with the influx of demons in human territory. 

“What,” Kaoru starts, but his voice cracks and betrays him. He swallows, and the fabric of Rei’s gloved hand traces his throat as he does it. “What promise did you make?”

“To protect you,” Rei says. He presses his bare fingers to the side of Kaoru’s head, where skin made contact with cement. It stings, and Rei’s fingers come away bloody, and Kaoru watches with something like morbid fascination as Rei brings his hand back to taste the blood.

It isn’t a common rule, to not give demons your blood. It isn’t the one most frequently broken, because in general, if a demon is drinking your blood, you’re already dead, and the mistakes have already been made. 

It’s still a pretty bad idea.

“Why?” Kaoru asks.

Rei smiles. “That’s between your mother and I,” he says, “but it’s a pact I have no intention of breaking.”

Everything about Rei is halfway familiar; his archaic language, the smell of iron and spice, the sound his clothing makes when he moves, the jet black painted nails, his _eyes_. Kaoru can’t make sense of any of it. He keeps reaching back in his memory to that day that he must have first met Rei, when he was safe in his mother’s arms and the idea of losing her was nothing but a bad dream to be chased away by morning’s light. 

He can’t remember what she said to Rei. He can’t understand what she could have said to trap the king of hell into a pact like this. 

Kaoru reaches out, wrapping his fingers around Rei’s bare hand. It’s sticky with Kaoru’s own blood, and the reminder of how injured Kaoru is makes everything in his body ache, but he can’t keep breaking every rule on dealing with demons (with the _king of hell_ ) and expect to get out alive. 

“Swear it,” Kaoru says, clenching at Rei’s hand with every last shred of strength he can still manage. “Swear--”

“I swear,” Rei says, swiftly interrupting. There’s a preternatural glow in his eyes that only gets stronger as he speaks, the ground beneath them both tracing out the glowing red lines of a summoning circle that Kaoru has only ever seen in the oldest of his mother’s books. “As Rei Sakuma, the missing king of hell, that I will protect you to the best of my ability, until I am no longer alive.”

The enormity of it renders Kaoru speechless, because he knows what that means. He knows the significance -- an oath that binding, when Rei has already tasted Kaoru’s blood, with the light of the circle around them? There’s no one that could break that. 

“Do you accept?” Rei says. 

Kaoru is fairly certain that making a pact with a demon is another one high up on the list of rules he shouldn’t be breaking. On the other hand, his mom definitely did it first, and if anyone can handle a demon, it would have been her. She managed to handle Kaoru’s father, after all.

“I accept,” Kaoru says, cautiously, because this is uncharted territory. He doesn’t know what accepting means, really, other than Rei’s protection. He doesn’t know how much this is going to cost him, if his soul is going to be pulled away from him later on, if this is all a very bad dream that he’s going to wake up from at any moment.

Rei’s power flares, the circle blindingly bright. The last thing that Kaoru distinctly remembers is Rei’s eyes, the same color as the circle, and the city alarms screaming in his ears.

Everything Kaoru can see is red and black, and he thinks that maybe he’s made a mistake for a split second before the bloody darkness takes him.


	2. Chapter 2

Kaoru wakes up to the sound of rain. His alarm clock is flickering at him, telling him the time is midnight. The storm must have knocked the power out, for a few minutes. Kaoru lays in bed for a few moments, raising an arm to flop above his head on the pillow while he shuffles his mind closer to actually being conscious.

It’s been raining an awful lot, Kaoru feels like. It’s not usual for it to be raining so much in October, but he doesn’t know that much about weather. It was raining yesterday, when he…

Kaoru sits bolt upright in his bed. There’s no pain when he moves, and when he touches his shoulder underneath his worn sleep t-shirt, there’s only unbroken skin. A quick glance in the mirror reassures him that he doesn’t have a concussion, and Kaoru exhales, slowly. What a weird dream to have. 

It’s dark outside, even accounting for the continuing rain. The streetlights light up the wet street until the world looks glossy, and Kaoru slips out of bed to pull the curtains shut against the periodic flashes of lightning. He isn’t afraid of thunder, but he still feels on edge from that dream. He’d heard that if you died in your dream, you died in real life, but maybe that isn’t true? Though, Kaoru supposes, he didn’t technically _die_ in that dream… 

Half on autopilot, Kaoru heads to the bathroom. His head still feels foggy from sleep, and he can’t figure out if it’s because he had too much rest or not enough. He turns the bath on to run and gets ready to shower off, running a hand through his hair. It’s a good thing his dad’s still on a trip; Kaoru doesn’t want to deal with any weird questions about why he’s taking a bath at who-knows-o’clock. As he’s stripping out of his shirt he tries to remember the last thing that wasn’t part of the dream -- getting home? School…? Everything is a little bit blurry.

Kaoru drops his shirt and turns to start tugging off his boxers when he catches sight of something in the bathroom mirror. Something conspicuously on his shoulder, right where the demon had clawed him hard enough that his arm felt like it might fall off -- 

No. That was a dream. Wasn’t it?

“What the hell?” Kaoru murmurs, twisting to get a better look at it. His stomach sinks like a lead weight, because there’s no mistaking the sight of a demonic seal, black ink spread across the tanned flesh of his shoulder. He hasn’t seen a seal like this outside of his mother’s books in his entire life. The only demons that can make contracts with people are high-level demons, demons that stopped existing during the war, decades ago, so--

Kaoru presses on the seal with fingertips that are shaking more than he’d like. He has to be hallucinating, this has to still be a dream, none of this can be real. 

He can feel the sensation of panic starting to well up in his chest when the seal glows red and a shadow appears behind Kaoru, visible in the mirror.

Kaoru can’t help it. He screams. He’d like to think of it more as a startled yelp, but it’s still loud and echoes in the bathroom. He jerks around and slips on the tile floor, cascading backwards and bracing himself for the inevitable fall and brand new concussion -- but Rei’s hand snaps out of the shadows, grabbing Kaoru by the wrist before he can fall.

The rest of Rei’s body emerges as he steps forward, shadows melting away, and part of Kaoru can’t help but think how ridiculous a fully-dressed king of hell looks under the bright fluorescent lights of a modern day bathroom. 

“Good evening,” Rei offers, like he isn’t entirely out of place. He lowers Kaoru to the floor, and Kaoru sits there, stunned for a second, before remembering that he’s in his bathroom, in his underwear, in front of _Rei Sakuma, literal demon king of hell_

“Why are you in my bathroom?!” is the first thing Kaoru can think to demand. He scrambles back up to his feet, ripping his wrist out of Rei’s grasp. Rei doesn’t fight him, letting go calmly and bringing the hand back up to tap thoughtfully at his cheek.

“You called for me, didn’t you…?” Rei says. He looks at Kaoru, and Kaoru does his best not to blush, but there’s really only so many battles Kaoru can possibly fight when he’s mostly-naked in front of a guy that’s also the king of hell.

“I didn’t call for you!” Kaoru objects, grabbing a towel and wrapping it around his waist. It really doesn’t cover much more than his underwear, but it makes Kaoru feel a little better. 

Rei steps forward, and Kaoru steps backward, back pressing against the wall of his bathroom. It suddenly seems like a terrifyingly tiny space, because Kaoru has never had to share the bathroom with anyone else before. Rei steps forward again, until there’s mere centimeters between the two of them, hand reaching out to press flat against the wall.

Kaoru’s never actually been on this side of the position, before. It feels a lot more claustrophobic than he was expecting, with the steam from the bath filling the room and the shadow of Rei’s body pressing down on him. 

Rei presses his other hand to Kaoru’s shoulder, fingertips dragging from collarbone over his skin to trace out the pattern of the seal. It’s the wrong side, but Kaoru can feel something where the seal rests on his back -- a jolt like a static shock and residual heat.

“You can call for me by name,” Rei says, and Kaoru tries very hard not to look at his fangs, “or with my seal.” 

“Sakuma-san,” Kaoru says, taking in a deep breath to try and steady himself, “please leave my bathroom.” 

Rei straightens back up, and as his hand leaves Kaoru, the heat on Kaoru’s back vanishes like it was never there. 

“Of course,” Rei says, and vanishes. 

Kaoru stares for a long moment at the place where Rei had been, trying to wrap his head around the fact that he apparently has a demon just hanging around him.

“Are you gone,” Kaoru asks the seemingly empty room, “or just invisible?”

There’s no response, and Kaoru relaxes, lowering the towel. He steps away from the bathroom wall and looks back at the mirror, one more time, taking in the sight of the seal marked into his flesh. It feels permanent in a way that Kaoru can’t quite articulate, like he’s already used to it being there. The idea of it being gone isn’t something that makes him happy, and he doesn’t quite know what to make of that.

Stripping off his underwear, Kaoru decides that he’ll feel better after a bath. It isn’t until he’s scrubbed clean and relaxed back in the bath tub that he realizes if the entire encounter with Rei wasn’t a dream, then _how did he get into his pyjamas_?

-

Rei is spread out on the couch with his eyes closed when Kaoru walks into the living room after his bath. He’d look peaceful, but the fact that he’s in leather and silver chains kind of dampens the entire effect, Kaoru thinks. Rei turns his head towards Kaoru as Kaoru strides into the kitchen, and Kaoru staunchly refuses to meet his gaze.

“Do you eat?” Kaoru asks, opening the fridge. “Like, human food?”

“I don’t need to,” Rei answers, and he’s suddenly _there_ , standing right behind the open door of the refrigerator, and Kaoru can’t help but jump backwards and slam his spine into the edge of the kitchen counter. 

“Ow--” Kaoru starts, and then Rei is even _closer_ , standing between Kaoru and the refrigerator door and putting one of his hands on Kaoru’s hip. Rei is frowning, just a little, and every single warning bell in Kaoru’s head is screaming as loud as possible that not only is there a guy violating every known law of personal space, but it’s the _king of hell_. 

“What are you doing,” Kaoru says, the end of his sentence dropping off before he can form a real question, eyes staring pointedly at Rei’s exposed collarbone. That’s safer than looking into his eyes, especially when he’s so close. Most of the demons these days don’t have the same powers that older ones did, and Kaoru can’t remember the last time he heard about a human falling for a demon’s allure or getting hypnotized by their gaze, but Kaoru also can’t remember the last time anyone thought the king of hell was alive, so clearly the entire playbook has just been thrown out.

“You’re hurt,” Rei says, and his hand moves from Kaoru’s hip to Kaoru’s back, slipping under the loose shirt and pressing against still-warm skin from the bath. Kaoru can’t help but gasp when Rei’s fingers touch the sensitive skin, still stinging from the impact with the counter. Kaoru’s hands grab onto Rei for a split second to steady himself, and then he flattens his palm against Rei’s chest and shoves himself backwards. Rei’s grip is like iron even with just one arm around Kaoru, and all Kaoru succeeds in doing is winding up with more of himself in contact with Rei.

“I’m fine,” Kaoru insists carefully, trying to get his bearings back before he does something that gets him in even deeper. Not that you can really get much deeper than a binding contract with a demonic king, but… “You can let go.”

Rei doesn’t move for a second, and it draws out long enough that for a second, Kaoru thinks Rei isn’t going to let him go at all -- but then Rei steps back, removing his hands from Kaoru. Kaoru lowers his own hands, trying to ignore the heat in his cheeks, and moves around Rei to resume rummaging through the fridge for something to eat.

“You’re supposed to protect me from other demons,” Kaoru says. He has no idea what he wants to eat, but he’s absolutely ravenous in a way that can only be satiated by a load of carbs, so hot cakes in the middle of the night it is. “Right? You don’t need to try and save me from every bruise.”

Rei doesn’t reply immediately, and Kaoru risks a glance at him. He isn’t looking directly at Kaoru; he’s looking down at the ground with an expression Kaoru can’t even begin to unravel.

“If you’re injured,” Rei says, finally, and their eyes lock for a second before Kaoru can think to look away, “and don’t want to be, then tell me, and I will heal you. I won’t endeavor to guard you from the injuries of a normal life, if that’s what you desire.” 

“Yeah,” Kaoru agrees, but he sounds a little uncertain even to himself, holding an egg in his hand and backlit by his fridge. Unraveling what Rei says is a little hard, when everything he says is so archaic -- who even uses language like that anymore? -- but Kaoru doesn’t think their issue is exactly communication. “That’s great.”

Kaoru sets the ingredients he needs on the counter, flicking the kitchen light on properly so he can see what he’s doing. Rei doesn’t say anything, just moves out of the way and leans against the opposite wall of the kitchen, and Kaoru is internally grateful for the brief respite from trying to make conversation. He needs to gather his thoughts. 

“So,” Kaoru says, once he doesn’t have any mixing to distract him, hot cake batter sizzling gently in the pan. “About this whole contract thing… You’re gonna have to tell me what it entails. It’s not really a thing anymore, you know?”

Rei hums behind him, a thoughtful, easy noise. “To think that humans would have lost the meaning of contracts,” he says, like he can’t quite believe it. 

“The kind of demons you can make contracts with have been dead for a hundred years,” Kaoru says, gesturing vaguely with his spatula and continuing to look safely at batter in the pan. “That’s probably not long for you, but it’s a pretty long time for humans.”

“I thought humanity aimed to archive information on demons.”

“Yeah, but a hundred years is a long time for a book to last, especially when we’ve been losing ground this whole time,” Kaoru says. It feels weird to try and explain humanity’s role in the war to a demon, but then again, it’s pretty weird to have a demon in his house at all. “The information everyone saved was the kind that could help us out -- that didn’t really include contracts that couldn’t be made anymore.”

It’s possible that telling Rei how much Kaoru _doesn’t_ know about this whole thing is going to put him at a disadvantage. Demons can lie, after all, and even if Rei swore he was here to protect Kaoru, that’s still a fair bit of leeway in how truthful Rei needs to be. 

Kaoru doesn’t get the feeling that Rei is the lying type, though. He doesn’t know a whole lot about the king of hell -- even in his mom’s old books, there wasn’t exactly a lot of information -- but everything he’s heard says that the king wasn’t the sort to rule with treachery.

“The contract binds us to each other,” Rei explains. “I’ll be able to know where you are, and if there are any other demons in proximity to you, and you will be able to call me at a moment’s notice with the seal or with my name.”

“Are you just… too strong for the city wards to matter?” Kaoru asks. He pokes at the edge of the hot cake with his spatula, but it isn’t actually ready to be flipped over yet.

“They’re troublesome, but manageable,” Rei says. “They’re designed to keep demons without intelligence out, and they aren’t even perfect at that.”

“So, the wards on my house…”

“Ah,” Rei says, sounding slightly apologetic. “I dismantled those. They were like tiny papercuts -- ineffective, but annoying. You won’t need them, if I’m here.”

“My dad lives here too,” Kaoru says, and then quickly amends: “Sometimes.” Not this week, but that’s really for the best.

“I can restore them,” Rei says, “and simply include an allowance for myself.”

“You’ve got a week before my dad gets back,” Kaoru says. He flips the hot cake, and then broaches the real part of the conversation he doesn’t actually want to have. “You brought me back here… right?”

“Yes.”

“How’d you know where I lived?”

“It was on your identification card,” Rei offers, sounding somewhat amused. 

How does a demon even know what an ID is…? “Did you, uh. Did you change my clothes?” Kaoru asks, because this is the crux of the issue that his mind keeps getting stuck on -- the fact that he was definitely bloody in his school uniform when he passed out, and he woke up fresh as a daisy in his pyjamas. 

“Yes,” Rei says. “I’m capable of healing most of your wounds, but not your clothing. I didn’t think you’d relish the idea of waking up covered in the remnants of the fight.”

“It’s weirder to change my clothes,” Kaoru says. “That’s not the kind of thing guys do for each other.”

Rei is quiet long enough that Kaoru risks a glance over his shoulder, this time. Rei is giving a very intense stare to the spice rack, lips pressed together and arms crossed, and Kaoru’s stomach gives an anxious flip.

“I mean, it’s fine,” Kaoru continues, a little hurriedly, filling the air with words before the silence drags them both down. “But in the future, I’d rather change myself. You’re not bound to listen to me, are you? Like, can I give you orders?”

“No,” Rei answers. “The contract was for protection, not submission, but I have no reason to make you unhappy by refusing you.”

There’s something in Rei’s voice that Kaoru almost recognizes -- tight and very careful, as though every word is being laid on a battleground full of hidden landmines.

“Sorry,” Kaoru says, pushing the spatula back under his hotcake and pouring some more batter into the pan. “I didn’t mean… I don’t want to say something without thinking and then it turns out you have to listen to me.”

Mentally, Kaoru tries to think of the few things he’s demanded of Rei. He’s been treating Rei half like a human and half like a demon, and it’s leaving Kaoru in a strange space where he isn’t quite sure what he should be doing. 

“You _don’t_ want me to listen to your wishes?” Rei says, but there’s amusement in his voice, and Kaoru’s stomach slowly unravels the anxiety that was starting to clench it shut. 

“Listen,” Kaoru says, “I don’t know what I’m doing, here.” He turns around, facing Rei, and a part of him marvels at how absurd this scene must be -- a seventeen year old schoolboy in his sleep clothes facing down the demon king of hell in a domestic kitchen. “I’ve never made a contract with a demon, and I’ve definitely never tried to have a conversation with a demon before. I don’t know why you promised my mom you’d protect me, and for all I know she had something on you that means you’re going to turn around and kill me one day.”

“And still,” Rei says, a smooth interjection. “You’re afraid of being rude, or hurting my feelings. Is that it?” 

When Rei smiles, Kaoru can see his fangs, and Kaoru turns right back around to give his hot cakes attention. 

“I mean,” Kaoru says, because denying it would be pointless, “I just don’t want to be an asshole, and I really don’t want to be an asshole on accident, just because I don’t know what’s going on, or what demon etiquette is.”

“How can I help you?”

“Just,” Kaoru says, prodding at the edge of the hot cake again. “Explain what’s going on. As much as you can.” Kaoru wants to hear all the parts with his mother in them, even if he doesn’t think that Rei is going to include them. Some of her old notebooks are still packed away in the attic, with the old, leatherbound books that included all the information on demons from a century ago, and Kaoru thinks he’s going to have to make an effort to go dig them out later.

“And don’t go into the bathroom when I’m undressed,” Kaoru adds, as an afterthought. 

“Of course,” Rei offers. 

“And,” Kaoru starts, and then stops, because he’s making a lot of demands of Rei (the _king of demons_ , he reminds himself), “I don’t mind you teleporting, or whatever it is you do, but if you could just be a visible person… demon, inside the house.” So that Kaoru stops getting _startled_ all the time, because his body can only take so many bruises, and if Rei winds up that close to him again Kaoru is going to start thinking thoughts that he absolutely shouldn’t be thinking about guys, and especially not guys who also rule over hell.

“What would you prefer I do in public?” Rei asks. 

“Uh,” Kaoru starts, because he hasn’t actually thought as far ahead on that as he should have. “Are you planning to follow me around outside, too?”

“Of course,” Rei says. “I won’t be existing anywhere but this plane until our contract ends, but I need not be visible, if you’re worried about appearances.” 

“I mean,” Kaoru says, flipping the hot cake onto a second plate. He moves over to the kitchen table, setting both plates down and pushing one across the table. “Your eyes are pretty demonic, and you’re not exactly dressed very… subtle, but I don’t like the idea of you lurking behind me invisible, either.”

Rei looks at the plate with open bafflement for a moment. As he steps towards the table, his clothing changes, shifting into an image of Kaoru’s own uniform, complete with t-shirt on underneath and an unbuttoned jacket. 

“I can control what others perceive, when it comes to my appearance,” Rei says, sitting down at the table like his casual show of power wasn’t anything unusual. “I can hide my eyes from others, but not from you.”

“Uh,” Kaoru starts, and then shakes himself out of freezing up by passing Rei utensils, setting the syrup on the table. He never thought of busy work as something he would take advantage of to get out of an awkward situation, but focusing on his midnight snack seems preferable to dealing with the actual demon king in the room. “So they’ll just appear brown or something to everyone else?”

“Unless they’re an extremely powerful onymouji,” Rei says. 

“What about your,” Kaoru hesitates before he can manage to get the word “fangs” out, and taps on his own, considerably less pointed, canines instead. “You know?”

“Oh,” Rei says. He frowns, raising a hand up to run across the surface of his teeth. “I can hide those, as well.” When Rei lowers his hand again, his teeth look almost normal -- a little pointed, perhaps, but nothing that would raise suspicion. Something about it seems so wrong that Kaoru balks a little at it, stabbing his hot cakes with a fork.

“It’s fine if it’s just me,” Kaoru says, waving his other hand as if he can dismiss all the awkwardness in the room with a thought. “Your teeth and your eyes and your -- clothes.”

“The last time I walked in your world, people hardly cared what anyone else looked like,” Rei muses. His fangs are back, as though they were never missing, and Kaoru can’t help but feel a little relieved. 

“The last time you were around was before the war, wasn’t it?” Kaoru asks, and takes the opportunity to actually eat the hot cakes before they get cold.

Rei nods, calmly cutting his portion into bite-sized pieces before he even tries to eat it. Apparently demons have good table manners. Kaoru supposes that isn’t _too_ surprising.

“I know very little about what has transpired in the human world since my disappearance,” Rei says, and his voice is soft and tired. 

“Why don’t you fill me in on everything I need to know about having a contract with you, and I’ll fill you in on what I know about the war?” Kaoru offers. He tries for a smile, syrupy lips and all, and Rei’s eyes widen before the demon looks away.

“I’ll tell you all that I can,” Rei promises the wood grain of the kitchen table. 

“Okay,” Kaoru says. Honestly, he’s grateful it was so easy; Rei seems… easy to get along with, and if Kaoru doesn’t focus on his teeth or his eyes or the seal Kaoru can feel on his shoulder, it’s easy to forget that Rei isn’t human. “I’ll start. As far as humans know, the war started when the king of hell was killed, and all the demons poured out of hell into earth.”

“That’s accurate,” Rei says. “I wasn’t killed, but I was injured, and incapable of holding the barrier between hell and your world.”

“Who was trying to kill you?” Kaoru asks. 

“God,” Rei answers, and then promptly eats a piece of hot cake to prevent any further elaboration on that particular subject. Kaoru can recognize a subject dodge when he sees one, and he doesn’t press. “I was little more than the feral demons that attack the human barriers, when your mother struck her deal with me. I promised to protect you from all of my kind.”

“Why now?” Kaoru asks, because that’s what’s been pressing on his mind the most about all of this. Why now, so suddenly, when it’s been years since Kaoru’s mother died, years since the deal was made.

“Your birthday,” Rei answers. 

“What?” 

Rei hesitates before answering, dragging his fork soundlessly through the syrup on his plate and selecting his words with the utmost care. When he meets Kaoru’s gaze, Rei isn’t smiling.

“There are some humans born who have power,” Rei says. “Some of these humans go on to become onmyouji, but most are devoured, these days. Demons can smell power, and if a demon were to devour one with power, then that demon would, in turn, become more powerful.”

“Wait, wait,” Kaoru says, holding up a hand. “I’m not powerful at all. Am I? Was my mom? This is the first I’ve heard of--” 

Kaoru cuts off, abruptly, several things clicking into place. Why did his mother have so many books on demons, on the occult, even generations after the war? How did his mother wrangle the king of hell into a contract?

“You,” Rei says, looking at Kaoru with a gaze that’s so hungry it’s at odds with Rei’s antiquated style of talking, “are powerful enough that every demon in the city can smell you. On your birthday, you’ll be full grown into your power, but it will be truly _yours_. No one will be able to take it from you, demons or otherwise.”

“Was my mom strong, too? Did she have this power?” Kaoru can’t help the way his voice rises up around the edges. His food is all but forgotten, appetite vanishing in the face of the revelation of how much he doesn’t know, and he feels like it was just yesterday that he lost his mother. He feels as alone and confused as he did then.

“Yes,” Rei says, after a long pause. “There is substantial power in her line.”

“My siblings--”

“You were the only one,” Rei interrupts, before Kaoru can get any further in that train of thought, “to inherit her power.”

Kaoru settles back down in his chair, jaw working on nothing as he tries to absorb the information he’s being given.

“So once I turn eighteen,” Kaoru says, “that’s it, I’m fine? I won’t need your protection anymore?”

Rei looks away again, his gaze settling somewhere on the kitchen wall. “I will protect you from demons regardless of your age, but you will likely find little need for me.”

“Okay,” Kaoru says. “Okay. That’s -- okay.” 

It’s a lot, honestly. Kaoru is used to breezing through life, and finding out how many secrets about his mom he doesn’t know is a tough pill to swallow. 

“I’m going to bed,” Kaoru says, after a second. He hasn’t finished his food, but his appetite is gone, mind tripping over itself as it tries to sort through all the things he’s learned. He drops his plate into the sink, leftover hot cakes and all, and Rei doesn’t stop him. Rei doesn’t move, actually, just sits at the table with his arms crossed staring a hole into his plate.

Rei doesn’t follow him back upstairs, and Kaoru counts it as a blessing, because the last thing he wants to deal with right now is looking at Rei. Tomorrow, he’ll have to go into the attic and find his mom’s stuff; his dad hadn’t gotten rid of most of it, just boxed it all up… Kaoru isn’t sure exactly what he’s looking for, but it’s worth searching through to find anything he can. Anything about why he’s supposedly powerful, or what power his mother had, or how she could be so powerful that she could get the king of hell to make a contract…

Kaoru wants to know more about Rei, too. Kaoru drops onto his bed, staring up at the ceiling and knowing that sleep isn’t going to come easily. He doesn’t bother to set his alarm; there’s no way he’s going to school tomorrow. Not when the king of hell is going to be by his side, not with a bunch of other demons after his blood.

Kaoru keeps his eyes open in the dim light of his bedroom and tries to sort through his thoughts, but keeps coming back to Rei’s eyes, to the look on his face when Kaoru said he wouldn’t need Rei’s protection anymore. 

Nothing makes any sense, and Kaoru feels as lost as he did when he first found out his mother was dead. 

By the time Kaoru finally falls asleep, the sun is creeping up behind his curtains, and it lets him feel safe enough to drift off. It sounds like the rain has finally stopped.


	3. Chapter 3

Kaoru sleeps in until nearly noon. When he wakes up, it’s because the sun is too bright to keep ignoring, and he feels like he’s slowly smothering himself keeping his head underneath his pillow. He finally pulls the pillow off his face, squinting at the light streaming in through the curtains. At least it’s not raining again; the bright, beaming sunlight will do just as much to keep demons at bay as all the city wards will.

Speaking of demons… Kaoru sits up and is pleased to find that at least Rei hasn’t come into his room while he was sleeping. If Rei was being honest about not being invisible inside the house, then Kaoru could relax for a few minutes and try to regain his bearings. 

Skipping school isn’t exactly the most mature decision he’s ever made, but Kaoru feels it’s warranted. At any rate, he has another month before he has to start really staring down adulthood. He might as well enjoy his relative freedom while he can, given how much his siblings already sacrificed for his sake.

Kaoru opens the bedroom door, leaning out and looking one way and then the other. “Sakuma-san?” he calls, tentative, like someone calling to an intruder they’re not actually sure is in their home.

“Yes?” Rei says, materializing next to Kaoru. Kaoru jerks back, holding onto the knob of his bedroom door like it might either save him or keep him upright. It manages the latter, at the least.

“--Don’t do that!” Kaoru says. He doesn’t mean to snap, but he can’t help but be annoyed at being startled in his own house when he’s meant to be alone.

“My apologies,” Rei offers, offering Kaoru little more than a perfunctory inclination of the head. “You’ll have to bear with teaching an old man new tricks, I’m afraid. I’ll aim not to startle you so badly in the future.”

“Thanks,” Kaoru says, and then sighs. “I was just checking to make sure you were -- uh, okay, I guess.”

Rei looks at him, wordlessly, and Kaoru gets the distinct impression that he’s putting his foot in his mouth. So he keeps talking in a desperate bid to cover it, raising a hand up to finger comb through his hair as a nervous gesture. He probably looks like hell. 

“You know, since you’re a demon, and it’s really sunny out…?” Kaoru offers. He’d really, really like a clearly-written guide on how to interact with demons, but he somehow doubts he can just waltz into the local shrine and ask for a pamphlet about what to do when the king of hell makes a contract with you. Wow, he can just picture Hasumi’s face, actually. 

“I’m weaker in the sun, and would greatly prefer to spend as little time awake in the daylight hours as possible, but I’m still more than capable of protecting you even on the brightest of summer days,” Rei says, with a lazily sweep of his hand. He seems even more tired than he did last night, but Kaoru supposes that tracks pretty well, if Rei is usually a night sort of.. Demon.

“I wasn’t trying to doubt you,” Kaoru offers, pulling awkwardly on the bit of hair that tends to fall over his shoulder. All of this is new territory to him, and he has no idea how to treat Rei other than “not like a girl” and “not like a classmate”. 

“You have no need to be… worried, if that was what you were experiencing,” Rei says, and Kaoru finds it more reassuring than anything else so far that Rei doesn’t seem quite at ease with the situation either. 

“I don’t really know how demons work or anything,” Kaoru offers. “For all I know you spontaneously combust in sunlight or need to eat the soul of a virgin on a full moon or something.”

“Ah. No, I don’t eat souls for power, and killing me is quite difficult, as many people have found,” Rei says. “However, I’m not nearly as restored to power as I would like to be, under the circumstances, so sunlight is a bit more cumbersome than it would be otherwise.”

“Is there anything that I can do to help?” Kaoru offers, and when Rei looks at him, eyes wide, Kaoru holds up his hands. “I mean -- it’s in my best interest if you’re strong, right? You still can’t break the contract, but you could protect me easier…?”

“You aren’t in any danger even if I’m not as strong as I once was,” Rei says, and there’s something urgent in his tone, like he’s trying to convince himself as much as Kaoru. “The things that would restore me are… beyond your capabilities.”

“Even though I’m apparently the most powerful guy on the block?” Kaoru asks, aiming for humor but not quite managing it with the way his voice wavers.

“Your blood,” Rei says, bluntly, “would restore me, and that’s the easiest of the things that you could offer me.” 

Kaoru freezes, eyes zeroing back in on those fangs before he averts his gaze entirely. 

“You’re not gonna -- bite anyone else if I say no, right?” Kaoru ventures, hesitantly, because if it comes down to it, he really isn’t sure how much he’s willing to sacrifice for people he’s never met.

Rei looks away, leaning against the hallway wall. His arms cross again, black nails tapping on the sleeve of his shirt. It looks like he’s making an effort to tone down the leather, even if Kaoru questions the point of owning a black button up shirt with tiny silver bats on it.

“It would restore me to power more quickly,” Rei says, very slowly and deliberately, “but I won’t injure unwilling humans unless they fit certain criteria. I am bound only to you, so it is within the scope of my power to devour anyone, but I prefer to taste only the willing or those who would not be missed by society’s standards -- yours or mine.”

The idea of demon’s having a society is a little more than Kaoru wants to think about, for the moment, so he skips that half of the sentence.

“Okay,” Kaoru says. “That’s -- that’s fine, I guess, you can eat all the criminals you want. That’s what you’re talking about, isn’t it?” Rei offers a small incline of his head, the barest of nods, and Kaoru tries to relax. The idea of Rei’s fangs sinking into someone’s throat -- sinking into _his_ throat -- is almost too much to bear, at the moment.

“I don’t require anything from you,” Rei says, and he sounds dispassionate and so very tired that Kaoru almost wants to tell him to go eat some random murderer if it’ll help. “The only thing that is necessary on your part is the seal that marks our covenant.”

Kaoru shifts his shoulder with the reminder, bringing a hand up to press on still-sensitive skin.

“If that’s all,” Rei says, pushing himself back up off the wall without looking at Kaoru. “I’d like to rest through the worst of the daylight.”

“Oh, yeah, there’s a guest room--” Kaoru starts, but Rei is gone before he can finish, disappearing into shadows the second Kaoru agrees. “--downstairs…” 

Kaoru gets the very distinct feeling that he’s fucked up in some intangible way, and sighs.

-

The attic is dustier than Kaoru remembers. That makes sense, because that’s kind of how dust works, but it’s so bad he already had to venture downstairs to find a bandana to pull around his face like he’s some sort of American Western cowboy villain. Even with that to block the worst of things, he still finds himself sneezing periodically, sending small clouds of dust swirling up in the air to catch the sunlight.

At least it’s well-organized up here. His sister and brother both left boxes behind when they moved out, their rooms swiftly converted into guest rooms and an office for his father. His sister’s things are closest to the door, labelled in her neat handwriting with her name and a short description of the contents -- old stuffed animals, extra bedding for a single bed she’ll never have need for again. His brother’s things are behind those, dustier still, labelled only with his name in thick black marks, their contents apparently unimportant. Kaoru edges his way around the boxes until he can get to the very back of the attic, where the boxes aren’t labelled anymore, just stacked around some old furniture.

Kaoru clears off the old chair that’s crammed into the corner (sneezing several more times as he does so) and then settles down, pulling the boxes towards him to start rooting through him. 

“I know you left your books here somewhere, mom,” Kaoru says, because talking outloud to her makes him feel a little less silly than talking to himself. It might reduce the risk of Rei inadvertently overhearing, but Kaoru isn’t entirely sure on that point.

After his mom died, his dad seemed pretty set on packing up all the reminders that she’d ever been alive. Kaoru tries not to think entirely uncharitably about it, because he assumes that somewhere, deep down, his father had at least the smallest modicum of love for his wife, but it’s hard to say. Aside from her photo downstairs, all of her belongings were ruthlessly packed up. She didn’t have much family left, by the time she died, and there wasn’t much sense in just throwing everything out -- so here it all is, in the attic, collecting dust.

“It’d be great if you had a book titled “facts about demons”,” Kaoru murmurs, shifting through the boxes. It takes him a couple boxes to manage to find one with books in it, and he starts digging through properly, sorting them all into stacks. There’s fiction books, mostly best sellers, that look completely untouched, and it isn’t until he gets into the layers of books underneath that he starts finding the older texts. Leatherbound, titles faded on their spines, pages yellow with age, Kaoru is careful when he opens them. Some of them are in English, and a quick skim tells him that he’ll need, at least, a dictionary along side this, because his conversational skills aren’t going to get him very far in vocabulary that went out of date before he was born. Some are in _Latin_ , and he puts those in a separate pile entirely, because he knows about six words of Latin and none of them are helpful. 

He doesn’t manage to find a book with a helpful “facts about demons” title, but he _does_ manage to find a journal with a floral pattern etched in silver ink on the front. Opening it reveals his mother’s neat script, flowing kanji and small drawings of things from her daily life -- cats, flowers, a few people. Kaoru flips through it, not quite willing to read his mother’s most personal thoughts, and then nearly drops the journal entirely.

There’s the exact seal he has on his shoulder, drawn on a page. Kaoru didn’t know the kanji for Rei’s name, before, but it’s unmistakable, there on the page next to the seal with the “king of hell” notation next to it.

This is exactly what Kaoru was hoping to find, honestly, but finding it is leaving him with mixed feelings. It confirms exactly how much about his mother he _doesn’t_ know, exactly how much there is left for him to discover. It feels like his mother had a whole secret life that Kaoru has missed out on knowing about. Would she have told him, if she had lived? Would she have taught him all the things she knew? Would she have warned him about his power, his birthday? 

Kaoru doesn’t know, but at least he has something of a starting point to try and find out. He tucks the journal under his arm, picking up a few of the books in Japanese that are about demons and heading downstairs with them. There’s no point in trying to go through everything in one day when he’s already found step one. He’s halfway down the stairs with his haul when there’s a knock at the door, and Kaoru freezes for a second before he reassures himself that it’s not like his dad would knock, and he isn’t due to be home for awhile anyway.

Kaoru jogs the rest of the way downstairs, setting the books on the living room table before he skids to the front door. 

“Hey,” Kaoru offers, blinking when his eyes meet the familiar, slicked-back hair of his classmate. He realizes, as he looks at Kuro’s faintly surprised look, that given he skipped school, he should probably at least pretend to be sick. 

Well, it’s too late now.

“Thought you were skippin’ on your birthday,” Kuro says, offering Kaoru a smile that clearly states that Kuro isn’t going to be the one to let anyone know Kaoru isn’t sick.

“Well… then too, probably,” Kaoru admits, running a hand through his hair. 

“Brought you some notes,” Kuro offers, pulling them out of his bag. “Sena took ‘em, so they should be reliable.”

“Thanks,” Kaoru says, and grabs the notes as Kuro holds them out, watching as Kuro’s eyes drift over Kaoru’s shoulder and widen slightly. Kaoru’s stomach drops, because aside from the hallway there isn’t a whole lot interesting to see inside his house. 

Kaoru glances back over his shoulder, unsurprised to see Rei standing there. How suspicious is the bat-print shirt, Kaoru wonders furtively? Does it scream ‘I’m the king of hell’ or just ‘I’m a little edgy and might be in a rock band’? Kuro can’t see the red eyes or the fangs, right, didn’t Rei say he could use magic to appear human -- 

“--Transfer student,” Kaoru says, blurting the lie without properly working through it in his head. Rei can’t pass for a cousin (and that would feel weird, besides, even if it might make more sense from a ‘knows my dead mom’ standpoint), and there’s still a moratorium on student exchanges until they can make sure America stops accidentally opening demonic gateways. “Family friend, so he came to stay here.” 

Rei steps up alongside Kaoru, leaning against the doorway and looking every bit like he should be plastered on the cover of a magazine titled _Demonic Bachelors Monthly: King of Hell Edition_. There would be a fold-out poster and an autograph, probably.

“Oh, hey,” Kuro says, and the way he breaks out into an easy smile makes Kaoru’s stomach unclench just a little. Kuro would definitely attack if he thought anything was weird, wouldn’t he? Kuro used to be in an anti-demon gang, or something. Kaoru vaguely remembers when he used to come to school with bruises only to get pulled out of class and lectured by the student council vice president. “Guess I get to meet you early.”

“This is Kuro Kiryuu,” Kaoru offers to Rei, swallowing down his nervousness at the fact that he’s introducing a classmate to a demon. God, now Rei’s definitely going to come to school with him, and Kaoru doesn’t know how he feels about _that_. “This is--” Kaoru cuts off, abruptly, unsure of if he should be giving Rei’s name out. Isn’t that important, for demons?

“Rei Sakuma,” Rei offers, with an incline of his head. 

“Nice to meet you, Sakuma,” Kuro offers. “Maybe you’ll get lucky and wind up in our class.”

“I wouldn’t call that ‘luck’.” Kaoru’s response is a little wry, because he’s well aware that their class is a little on the weird side -- but then again, it wouldn’t make much sense for Rei to let himself get placed in another class, so Kaoru has no idea how any of this is going to work. Demon magic? Should Kaoru be letting his teachers get spelled? 

“He’ll be fine if he’s got you to look out for him,” Kuro offers, and it’s such a wild reversal of the actual situation that Kaoru can’t help but laugh. He hopes it comes across as something other than nerves.

“Yeah,” Kaoru says, doing his best to deflect the entire thing. “Anyway… thanks for the notes.”

“No problem,” Kuro says. He steps back, securing his bag back on his shoulder. “See you tomorrow?”

“Yeah,” Kaoru says. Rei offers another miniscule incline of his head that could probably be assumed to be a nod, and Kaoru thanks whatever deity might be listening that it’s Kuro that delivered his notes and not, like, Sena, who would definitely have taken offense by now, or Morisawa, who would probably have tried to recruit Rei to a sentai-themed demon fighting brigade.

The second the door closes, Kaoru sighs, leaning back against it and letting himself feel some degree of relief. That’s… one person down on meeting Rei, and only about seventy more to go.

“So,” Kaoru says, “I guess you’re coming to school with me tomorrow.”

“That would be the safest option,” Rei replies.

“Why did you -- were you like, checking to make sure he wasn’t dangerous?” Kaoru asks. “He didn’t need to see you at all, right?” 

It comes out a little more like Kaoru is ashamed of having Rei around than Kaoru means for it to, but trying to navigate the subject of having a demon around is so complicated… 

“His line has demonic blood,” Rei says, not appearing to take offense. “It’s exceedingly diluted, but it was enough for me to be aware of his presence.”

“Is that normal?” Kaoru asks, glancing back at the door with unease. “For humans? Like -- he’s not going to try and eat me or anything, is he?”

“He doesn’t even have enough power to see my real form,” Rei says. “You shouldn’t need to worry.”

That’s reassuring, at least. The last thing Kaoru needs in his life is a classmate losing his mind and trying to eat Kaoru. It might make English class more interesting… 

“Is it okay for him to know your real name?” Kaoru asks. “That is your real name, isn’t it, Sakuma-san?”

“It is,” Rei says, “but I am already bound to you. In order to be tied to another master, someone would first need to end our contract.”

“How, uh--”

“By killing you,” Rei says, before Kaoru can even finish his sentence. Kaoru swallows, because he had a feeling that was what Rei was going to say. 

Kaoru nods, slowly, letting himself relax even though he wants to tense up. He’s been tense for days already, it feels like, even though it hasn’t been long at all since he made the contract with Rei. He isn’t used to living life this on edge.

“So you’ll protect me from getting eaten, and I’ll protect you by virtue of being alive, and -- uh, I guess you get to be a transfer student,” Kaoru says, offering Rei the breeziest smile he can muster. It’s not his greatest work, and it doesn’t seem to penetrate the brooding expression on Rei’s face, but, well, Kaoru _tried_.

“It would be better,” Rei says, slowly, as if he’s unsure that he should be saying anything, “if you avoided school, but if you insist upon attending, then I will do so as well.”

“I can’t skip school until my birthday,” Kaoru says. As it is, he doesn’t know how he’s going to manage to cover for any of this once his dad gets home. Sure, he can have Rei go invisible, but what if someone comes looking for Rei? What if the teachers want to send work home? Is Rei just going to use demon magic on everyone he meets? Is it _safe_ to demon brainwash everyone?

Ugh, he can feel his stomach clenching with anxiety, so he forcibly resets himself, lurches his brain out of the loop and looks at Rei.

“Hey,” Kaoru says, because there’s better things to worry about than how to deal with his dad. “How good is your English?”

-

As it turns out, Rei’s English is _flawless_. Kaoru isn’t sure exactly how demon magic works, but it seems to involve a lot of calm conversation and the teachers not questioning Rei at all -- of course he’s a new transfer student from England, of course he’s a family friend, of course all the paperwork was already done. It makes Kaoru a little uneasy how simple it all seems to be. It might be less of a headache than he’d thought, trying to deal with this mess once his father gets home.

Class goes about as well as it can, when there’s an attractive transfer student, and Kaoru quietly basks in the attention the girls of the class give him. It’s just attention by proxy, and he knows they’re more interested in Rei -- he can’t blame them, honestly -- but being able to look at Yuuki-chan’s smiling face is a nice reprieve from the craziness that his life has been for the past couple days.

Rei is a distraction in Kaoru’s peripheral vision all the way up to lunch, because as much as Kaoru would like to try and focus on his studies for more than thirty seconds at a time, _Kaoru_ can still see Rei’s fangs, his red eyes, the way his skin borders on too pale to be human. Even if it seems like everyone else is just as fooled by the magic that hides Rei’s identity, Kaoru can see through it, and the reminder that his new classmate-slash-roommate is actually a demon is both nerve-wracking and astonishingly easy to take for granted already.

“Hey,” Kaoru says, when it’s finally time for lunch and Kaoru has a break from trying to pretend he’s focusing on work when he is, in fact, focusing on how long Rei’s eyelashes are. That’s pretty illegal on a guy, isn’t it? “We didn’t bring a lunch. You wanna grab something?”

Rei leans back in his chair, looking for all the world like he’s a model trapped in an ordinary highschool setting. “I’ll be fine.”

“I’ve got extra,” Kuro says, looking a little hesitant as he calmly inserts himself into the conversation, holding up what is definitely a bento big enough for more than one person. 

“Who were you planning to feed?” Kaoru asks, because he’s been going to school long enough to know that even Kuro’s monster metabolism doesn’t take that much fuel.

“Martial arts club,” Kuro offers. “Tetsu’s skipping today; didn’t finish a home ec project.”

Kaoru wants to turn Kuro down just for the sake of avoiding a longer lunch conversation, but Kaoru is also the sort of person who thrives on friendship, and he finds that turning Kuro down takes a little more willpower than he has, at the moment.

“Sure,” Kaoru says, accepting for he and Rei without thinking about it. “Sounds great.”

Kuro pulls up a chair, and they all wind up crowding around Rei’s desk as the bento is unpacked. It’s exactly as cute as Kaoru would expect from someone like Kuro, all the apple slices cut into cute rabbits and the onigiri given little cat ears. He supposes when you’re as manly as Kuro is, it’s kind of a charm point to have such a cute side. 

Rei, for his part, produces a single carton of tomato juice from inside his school bag, delicately inserts the straw, and sips on it. 

“Is that all you’re eatin’?” Kuro asks, and Rei blinks at him.

“Jet lag,” Kaoru offers, and then silences any further protest by cramming more of an onigiri than strictly necessary into his mouth. “This is really good!”

“Yeah?” Kuro says, looking a little embarrassed and extremely pleased. “I’m glad. I used the same recipe for my little sister, but she’s always tellin’ me she can buy lunch these days…”

“Younger siblings are like that,” Rei says.

“I guess they are,” Kuro agrees, with a laugh in his voice.

“Hey, hey,” Kaoru objects, waving his chopsticks. “I’m the youngest in my family, you know?”

“Sorry, man,” Kuro says, without a trace of apology on his face. 

Kaoru puts on a sulk that’s entirely an act, and keeps it up until he looks at Rei, who is staring _directly_ at him, the intensity of his gaze hardly lessened by the school uniform. Kaoru swallows his bite, and then laughs, trying to redirect the conversation again.

He feels Rei’s gaze on him for the rest of lunch.

-

“That wasn’t so bad,” Kaoru says, when school is finally over and he and Rei are headed to the gates. Rei’s eyes are half lidded against the sun, his pale skin nearly translucent in the glare, but he manages to keep pace with Kaoru despite looking like he’s asleep on his feet.

“Was it meant to be?” Rei asks, and then stifles a yawn.

“Well,” Kaoru says, “I just meant, since you’re undercover in a school full of onmyouji and--”

“Kaoru-san!” 

Kaoru cuts off so abruptly he’s certain his heart skips a beat, head jerking over to look at the classmate barreling towards him. “Mikejima-kun,” he manages, hoping that his smile doesn’t look like he’s caught in headlights.

Rei turns, a second slower, to view Madara, his lips pressed into an unimpressed line.

“I didn’t get a chance to meet your friend earlier!” Madara says, all exclamation points. His smile is as blinding as Chiaki’s, and he stands out even more against the sleepy appearance of Rei alongside him.

“Oh.” Honestly, Kaoru wishes he could avoid introducing Rei to as many people as possible in the hopes that no one could catch on, but -- well, that ship has long since sailed.

“I’m Mikejima Madara! You can call me Mama-san,” Madara says, shooting his hand out towards Rei.

Rei looks at him, languid and slow, and then takes his hand. “Mikejima-kun,” he offers. “I’m Rei Sakuma. It’s nice to meet you.”

Madara shakes Rei’s hand with no small amount of vigor, but his smile is sharp enough that it makes Kaoru nervous. He knows that Madara is… a hunter, maybe…? He’s only at school about half the time, and he winds up with about as many mysterious scrapes as the rest of the class combined, and Kaoru vaguely remembers something about his mom being some sort of rogue demon hunter, maybe.

Kaoru wishes he’d paid more attention to his classmate’s backstories. 

“Where did you say you were from, Rei-kun?” Madara asks, and Kaoru nearly flinches at how informal the address is. It isn’t like Madara knows that Rei is the king of hell -- which is a good thing -- but Kaoru sure can’t forget it.

“I lived in England,” Rei answers.

Kaoru, attempting discretion, starts to slowly angle himself back towards the gates in an attempt to escape the prying conversation. Why couldn’t all of his classmates be as polite as Kuro and as uncaring as Izumi?

“I love England!” Madara says, switching to English fast enough that it makes Kaoru’s head spin. “Where did you live?”

“London,” Rei answers, placidly. He steps forward with Kaoru, starting the journey back to the front gates and freedom.

“What part?” Madara asks, and Kaoru gets the distinct impression that he’s prying on purpose. 

“Mikejima-kun--” Kaoru starts.

“It’s rare for anyone to be allowed on international flights, especially as a transfer student,” Madara says.

“My dad got him a travel pass,” Kaoru says, because there’s no way that Rei knows enough about the current political situation to cover for this kind of thing.

“Oh, is that it?” Madara says, sounding unconvinced, but in a way that doesn’t touch his smile. If anything, that makes it even more threatening. “Your dad is pretty important!”

Kaoru’s laughter is way too nervous to pass as real, but they’re at the gate, so he sees his opportunity and he takes it. “Yeah,” he offers, “but we’ve gotta get home. We’ll see you later, Mikejima-kun.”

“Yeah,” Madara says, agreeably, backing up and waving as he goes. “I’ll see you tomorrow, Kaoru-kun! Or maybe tonight, right, Rei-kun?”

Kaoru’s mouth twitches, and then Madara is _gone_ , racing away like… well, a member of the track team.

“He’s strong,” Rei says, once they’ve parted from the crowd and escaped the crush of students all going home at the same time. 

“He’s a hunter, I think,” Kaoru says. He drifts a little closer to Rei as they pass out of the sphere of protection that the school offers, automatically, and tries not to think too hard about it -- it just means that Rei is stronger than all the other demons that could possibly attack, _that’s definitely it_. “His mom was a rogue, but I’m pretty sure the school made him register officially.”

Rei makes a considering noise, and when Kaoru looks at him his eyes are so brightly red that Kaoru worries it won't be disguised. Kaoru looks around instinctively, but there’s no one else around, there’s no one but the two of them and people that are far enough away that they probably can’t see Rei’s inhuman eyes.

“Is it going to be a problem?” Kaoru asks, and Rei shrugs up one shoulder, the motion fluid and easy even underneath the heavy fabric of the school uniform.

“Foretelling the future isn’t one of my powers,” Rei says, and Kaoru resists the urge to roll his eyes.

“Well, if he picks a fight or something because he figures it out, don’t hurt him, okay?” Kaoru says, uneasily. Rei fixes him with a gaze that’s entirely too piercing, looking at him for a long moment as they walk along the road home.

“As you wish,” Rei says, finally, after entirely too long, and looks away. 

Kaoru doesn’t know what to say in response to that, so he decides not to say anything at all. If he tries hard enough, he can pretend the silence is companionable as they walk home, and not awkward. He steels himself, trying to decide if he wants to try talking again.

“Hey,” he finally says, because there’s only so long a silence can drag on before it starts to become a physical sensation. “I didn’t mean--”

Rei’s arm comes out, grabbing Kaoru by the front of his shirt and dragging him across the road so quickly Kaoru barely has time to process anything before he’s bodily thrown into the concrete wall along the side of the road. Rei’s body slams against him a second later, knocking all the wind out of him, and Kaoru registers, faintly, that Rei is back to leather and black, the smell of smoke in the air. Rei whirls around a second later, and Kaoru wheezes faintly at the sight of at least three other demons all surging forward. One of them looks almost as human as Rei, horns curling out of his head and hands that fade into nothing but metal claws. 

The city’s alarms kick in on a delay, and Kaoru’s higher functioning takes a small vacation as he watches the way Rei fights -- fluid and ruthless, his hands a blur as he reaches out to snap the neck of the demon that surges forward first. 

The fight is short. Rei dispatches the least human of the demons first, and then turns his attention to the horned demon, who takes a step back and tries to run. The demon disappears in a burst of purple flame and a piercing shriek, and Kaoru can’t help the way his hands start shaking automatically.

Rei steps forward before the flames have even fully dissipated, crossing back over to Kaoru and tracing gloved fingers down Kaoru’s cheek.

“Are you hurt?” Rei asks, close enough that Kaoru can make out the sharp curve of his fangs and Kaoru’s own reflection in Rei’s eyes.

Kaoru wheezes in response. 

Rei leans forward, his hand on the back of Kaoru’s neck, and for a split second Kaoru is terrified that Rei is going to bite him, going to go against the contract that he swore -- but then darkness flares around them both. It’s a strangely comforting embrace, and Kaoru can’t tell if it’s the darkness or Rei’s arms or just the adrenaline that’s still surging through him, but he can feel the seal on his shoulder burning.

He opens his eyes to the sight of his bedroom. 

“Woah,” Kaoru says, and slowly releases the hold he didn’t realize he had on Rei’s shirt. “Did you just--”

“Are you hurt?” Rei says, again, his hand still on the back of Kaoru’s neck.

Kaoru flushes hot enough that he can feel it, stepping away from Rei and reaching up to scratch at the side of his face. 

“I’m okay,” Kaoru replies, embarrassed at how much a guy is getting to him like this -- even if he is a preternaturally beautiful guy. “Thanks. I didn’t know you could, uh, teleport?”

“It takes more energy than I can afford to expend regularly,” Rei says, and he steps away, crossing his arms and glancing at Kaoru’s wall. “In emergencies, I’m capable.”

“That’s pretty cool,” Kaoru says, trying to pretend like everything is normal. When he glances at Rei, Rei carefully meets his gaze, and Kaoru feels a little more like the ground underneath him is solid enough for him to stand on. 

“If you find that you’re injured,” Rei says, and his voice is softer than Kaoru would have thought, “let me know.”

“You don’t need to spend your energy on that. It’s probably just a bruise or something.”

Rei looks unconvinced, but he nods all the same. 

“Anyway, I’m gonna shower,” Kaoru says, because it’s the first place he can think of that he knows Rei won’t follow him. He needs some time to be alone and think about the day and try to think of anything but the feeling of Rei’s body pressed against his on the concrete.

**Notes for the Chapter:**

> i haven't abandoned this i'm just extremely slow but i saw the gif of enstage rei licking his lips and wrote the rest of this in one sitting, thanks for fueling me koji


End file.
